<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			*{
				margin: 0;
				padding: 0;
			}
			html,
			body{
				width: 100%;
				height: 100%;
				overflow: hidden;
			}
			.wrap{
				width: 400px;
				height: 200px;
				border: 1px solid;
				border-radius: 50%;
				text-align: center;
				font: 20px/200px helvetica;
				position: relative;
			}
			.wrap::after{
				content: "";
				display: block;
				border: 1px solid;
				border-radius: 50%;
				width: 50px;
				height: 50px;
				position: absolute;
				right: -10px;
				bottom: -10px;
			}
			.wrap::before{
				content: "";
				display: block;
				border: 1px solid;
				border-radius: 50%;
				width: 30px;
				height: 30px;
				position: absolute;
				right: -40px;
				bottom: -30px;
			}
		</style>
	</head>
	<body>
		<div class="wrap">这是一个对话框的绘制练习</div>
	</body>
</html>
